The federal government has identified more safety problems with human research at the University of Washington, prompting the school to halt further enrollment in a genetic study.

It's the second time this year that the university has been warned about its procedures involving human research.

This time the school did not fully disclose to test subjects the risks involved in an ongoing genetic study or do enough to protect the confidentiality of their genetic information, according to the federal Office for Human Research Protections, which oversees government-funded human experiments for safety.

University officials were notified of the problems Sept. 9.

"We will respond to each of these concerns," the university said in a letter to the agency dated Friday.

Researchers have ceased enrollment in the study, which had involved 1,884 people. In the letter, officials said they'd received "no reports of harm to subjects, breaches of confidentiality or complaints."

The university each year receives millions of dollars in research funding from the National Institutes of Health and other federal agencies to maintain its more than 5,600 human experiments.

In their latest findings, federal officials questioned how procedures were conducted regarding a genetic experiment by Dr. Phillip Chance. Since 1998, Chance and collaborators in other states and countries have collected blood from families with rare inherited diseases to locate the genes responsible.

The federal research office was concerned that the school safety board monitoring the study didn't question Chance when he increased the number of planned enrollments from 100 to "unlimited" and that it did not ensure that others were being monitored by their own safety boards.

It also found that the UW board failed to follow up on orders that consent forms include information detailing how participants' blood would be used, that participation was voluntary, or on potential risks such as emotional stress or possible denial of insurance coverage.

Inspectors found the consent forms were never updated, yet the board repeatedly renewed Chance's study.

Yesterday, Chance said participants were properly informed, and he said federal overseers were concerned only with the university's documentation of his consent forms and protocols.

Participants knew that involvement was voluntary, said Chance. And for years, he said, he planned to enroll an unlimited number of participants. He said he voluntarily halted future enrollment, adding that it would not harm his research.

"It's all about documentation. It had nothing to do with people being harmed," said Chance. "This is a huge undertaking. I'm sure the [university's oversight] boards are trying to do the right thing."

This is the eighth time in five years that problems have been found.

An audit in February revealed widespread problems in how the UW oversees human studies, including cases where projects with safety questions were allowed to proceed and instances where rules meant to protect children and prisoners were not followed.

The school has since added two more institutional review boards — there were previously seven — to monitor human research projects for safety.

The federal research office said the UW's response to those problems was adequate, and it cleared the school to resume three prison experiments halted in response to the audit.